Consumer devices such as Pocket PCs or palm-sized and handheld computers are limited in their available storage space. These devices are capable of loading and executing software packages in much the same way as a desktop computer, but lack the storage necessary to have several of these packages loaded onto the system concurrently along with other data needed by a user. Other devices such as cable television set-top boxes, satellite receivers and so forth have the same lack-of-memory problems.
As access to the Internet via such devices is being planned and to some extent implemented, the lack of storage on the devices create problems not seen in home or business computers. For example, personal site customizations, favorites, saved data such as credit card information, cookies and so forth are typically stored on computing devices having relatively large hard disks wherein storage is not normally an issue. E-mail files, which on a device such as a single set-top box, will differ for (possibly multiple) individual users of that device. However, saving such data along with other needed information would quickly fill up the available storage on many devices, and if, for example, a relatively large file was downloaded to the device, the saved data would have to be discarded in order to fit the large file. Indeed, in at least one contemporary cable television set-top box, only 128 kilobytes are available for persisting user data, which is several orders of magnitude smaller than the hundreds of megabytes to dozens of gigabytes typically provided by contemporary personal computers. Contemporary pocket-size devices have somewhat more memory, but are still on the order of tens megabytes or less, of which the operating system and stored programs consume a considerable amount.
While network shares allow greater amounts of storage to be accessed via remote drive connections, their implementations require constant connection to the network in order to access a network share. Among other drawbacks, this makes network shares unsuitable for use with the Internet. For example, NetBIOS and other drive-sharing (redirector) systems currently require constant communication between the server and the client. Data is not cached, but instead is used directly off the shared file system, and is updated immediately. This is not acceptable for Internet-based file sharing, as the Internet is unreliable, and can be susceptible to long delays in transmission. The NetBios service and SMB protocol are also point-to-point, relatively heavy, and do not scale well to large numbers of remote users and multiple servers. Other existing services are unable and/or impractical to provide a solution to these low memory problems.